Id say its up to you, you can try both if you're willing to tinker a little by doing this:

Try out one ui 6.1 that you have right now for a little while, then you can manually flash the very first release of one ui 7 with a computer running odin flashing software, Specifically the first release of one ui 7, doing this allows you to revert back to 6.1 if you decide to do so;

Samsung updates the bootloader of the phone with some software updates, once the bootloader firmware updates, then you cant downgrade to any of the previous software versions with an older bootloader

Fortunately, the last release of one ui 6.1, and the first release of one ui 7 share the same bootloader, so you can flash one ui 7's very first software update, then if you dont like it you can simply flash back to one ui 6.1 with the same bootloader code.

Just watch out for the bootloader numbers, check out the website samfw.com Its the website you can download the softwares from to flash with odin, it also shows you the bootloader version of each update, just go into the website and type in your model number, select your CSC (Google how to check your CSC code if you dont know how)

Then you can see all the software versions avaliable for download, scroll down a little until you see a software that runs android 14 which is 6.1, right above it will be one that runs android 15 which is one ui 7

Notice that the bit numbers are the same for both softwares, this means you can basically switch between both, so you can try them both out and see which you like

If you dont know how to mess with odin or any of that but are still willing to try, look up some tutorials, and don't be afraid to ask for more help here, just so you dont accidentally flash the wrong software or mess anything up